1. Field of Invention
The invention relates generally to a lens and encapsulant for a light-emitting diode (LED) and, more specifically, to an ultraviolet (UV) LED (UVLED).
2. Description of Related Art
Recently, LEDs emitting in the blue and UV range of the electromagnetic spectrum have been demonstrated. Light-emitting diodes (LEDs) are semiconductor devices that are used in many applications, including indicator lamps, displays such as motion picture displays, signage, solid-state lighting, medical, sensing, optical interconnects, and communications including free space and guided wave communications. Ever-improving LED materials and designs provide high brightness, high efficiency, and high-speed capability.
However, current LED encapsulation/lens technologies, such as epoxies or silicones, are suitable for blue and longer optical wavelengths, but not for UV light. UV light is absorbed by most polymeric encapsulants, causing degradation of the encapsulant and reduced light emission. Reduced light extraction, in turn leads to more UV absorption leading to inevitable catastrophic failure. It is problematic that there have been no intermediate-wavelength UV packaging technologies suitable for LEDs.